*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
.container{
    width: 870px;
    margin: auto;
}
.container::after {
    content: "";
    display: table;
    clear: both;
}
header{
    background: #61bae6;
}
nav{
    padding-top: 11px;
    padding-bottom: 11px;
}
nav .nav-center,
nav .nav-left,
nav .nav-right {
    float: left;
    width: 33.333333%;
}
nav .nav-left {
    height: 56px;
}
nav .nav-center {
    text-align: center;
}
nav .nav-right {
    text-align: right;
}
nav .nav-right a{
    color: #fff;
    font-size: 12px;
    font-weight: bold;
    text-decoration: none;
}
nav .nav-right a img{
    display: none;
}
/*banner部分*/
.col{
    width: 50%;
    float: left;
}
.banner{
    color: #ffffff;
}
.banner p{
    font-weight: bold;
}
.banner h1{
    font-weight: 300;
    margin-bottom: 25px;
    font-size: 36px;
}
.banner a{
    background-color: #2996cc;
    padding: 15px 53px;
    font-weight:bold;
    text-decoration: none;
    color: #ffffff;
    font-size: 12px;
    display: inline-block;
    border-radius: 2px;
    transition: 3s;
}
.banner a:hover{
    background-color: #1882b7;
}
.banner img{
    width: 100%;
    display: block;
}

/*页面的主体部分*/
main{
    margin-bottom: 60px;
}
main .col{
    width: 25%;
    float: left;
    text-align: center;
    padding-left: 10px;
    padding-right: 10px;
}
main img{
    margin-top: 60px;
    margin-bottom: 10px;
}
main h3{
    font-size: 14px;
    margin-bottom: 10px;
}
main p{
    font-size:14px;
    color: #657082;
}